Spectral Observations of Optical Emissions Associated With Terrestrial Gamma Ray Flashes

DOI: 
10.1029/2020GL090700
Publication date: 
24/01/2021
Main author: 
Heumesser, Matthias
IAA authors: 
Gordillo-Vazquez, Francisco J.;Luque, Alejandro;Pérez-Invernón, Francisco Javier
Authors: 
Heumesser, Matthias;Chanrion, Olivier;Neubert, Torsten;Christian, Hugh J.;Dimitriadou, Krystallia;Gordillo-Vazquez, Francisco J.;Luque, Alejandro;Pérez-Invernón, Francisco Javier;Blakeslee, Richard J.;Østgaard, Nikolai;Reglero, Victor;Köhn, Christoph
Journal: 
Geophysical Research Letters
Publication type: 
Article
Volume: 
48
Pages: 
e0700
Abstract: 
The Atmosphere Space Interactions Monitor measures Terrestrial Gamma Ray Flashes (TGFs) simultaneously with optical emissions from associated lightning activity. We analyzed optical measurements at 180-230, 337, and 777.4 nm related to 69 TGFs observed between June 2018 and October 2019. All TGFs are associated with optical emissions and 90% of them are at the onset of a large optical pulse, suggesting that they are connected with the initiation of current surges. A model of photon delay induced by cloud scattering suggests that the sources of the optical pulses are from 0.7 ms before to 4.4 ms after the TGFs, with a median of -10 ± 80 µs, and 1-5 km below the cloud top. The pulses have rise times comparable to lightning but longer durations. Pulse amplitudes at 337 nm are ∼3 times larger than at 777.4 nm. The results support the leader streamer mechanism for TGF generation.
Database: 
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2021GeoRL..48.0700H/abstract
ADS Bibcode: 
2021GeoRL..48.0700H
Keywords: 
ASIM;Cloud Optics;Leader;Streamer;TGF